bmex

BitMEx

Bitcoin Message Exchange (BitMEx) is a service for Bitcore that allows to send and receive messages between the nodes of a Bitcoin network

Requirements

• bitcore-lib
• bitcore-explorers
• insight-api

Set-up

• Install NVM: wget https://raw.githubusercontent.com/creationix/nvm/v0.33.1/install.sh | bash
• Install Node 4: nvm install 4
• Install NPM: apt-get install npm
• Install Bitcore requirements: apt-get install libzmq3-dev build-essential curl
• Install Bitcore: npm install -g bitcore
• Create your Bitcore full node: bitcore create [--testnet] BTC_NODE
• Install bitcore-explorers and insight-api. From your node folder: bitcore install insight-api; npm install bitcore-explorers
• Clone or download the bitmex repo in the node's node_module directory (this will be soon replaced by an integrated bitcore command)
• Add "bitmex" to the "services" in 'bitcore-node.json' configuration file in the Bitcore node folder. Optionally you can add the "web" service if you plan to use the web APIs.

Usage

In order to interact with the BitMEx service, you can use the 'bitcore call' API command.

The available commands are:

• getnetstatus: returns the Nodes in the network
• addnode: adds an existing Bitcoin node to the BM network; SYNTAX: 'addnode NAME PRIV_KEY'
• createnode: creates a new BM node; SYNTAX: 'createnode NAME'
• removenode: removes a node from the BM network; SYNTAX: 'removenode NAME'
• getnodestatus: returns funds and in/out messages for a BM node; SYNTAX: 'getnodestatus NAME'
• sendmessage: sends a message from one BM node to another; SYNTAX: 'sendmessage NAME {NAME|ADDR} MESSAGE'
• getmessages: retrieves all BM messages for a BM node; ; SYNTAX: 'getmessages NAME'
• waitmessage: wait for a new BM message for the local BM network; SYNTAX: 'waitmessage'
• waitmessagefrom: wait for a new BM message from a specific source address; SYNTAX: 'waitmessagefrom {NAME|ADDR}'
• waitmessageto: wait for a new BM message to a specific source address; SYNTAX: 'waitmessage NAME'

BitMEx protocol details

Messages are splitted into chunks, each of which is embedded into a transaction, through the OP_RETURN Script command. Each transaction sends 546 satoshis (the minimum valid amount), and adds a fee of 3000 (a little higher than the minimum required by Bitcore).

The format of the message is:

0-1 2 3 4-79

| | | 'BM' | len | seq | message_chunk | |___________________________________|

Limitations

• BitMEx does not encrypt private key, so they are currently stored in clear on the hard drive
• Nodes need funds to send messages. (I plained to add an automatica faucet request, for Testnet)
• BitMEx currently support one network per-node (but its design allows to handle multiple ones, so it will be implemented soon)